The "p" and "i" designations below stand for "progressive" and "interlaced." For the progressive format, the full picture updates every 1/60 th of a second. For the interlaced format, only half of the picture is updated every 1/60 th of a second.

The 720p image format has almost three times as many pixels than either 480i or 480p formats.

The 1080i and 1080p formats have over twice as many pixels (2.25 to be exact) as the 720p format.

The 1080i and 1080p formats have over six times as many pixels as the 480i/480p format.

As you may have realized by now, most digital cameras today have a higher resolution than the highest HDTV picture resolution (1080i or 1080p). If you display a 10 mega pixel picture from your digital camera on your HDTV you will be discarding almost 4/5ths of the information (I.E. pixels).